Metalink support

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twanj
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Metalink support

Post by twanj » Fri Jan 19, 2007 5:33 pm


mb
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Re: Metalink support

Post by mb » Fri Jan 19, 2007 11:24 pm

Hello ..

I've quickly wrote an importer for the metalink v3 format. To test it download the latest version from
https://www.smartftp.com/download
Then in the Transfer Queue tab, click on the Add button. Then select the "*.metalink" file. The import adds the files to the Temporary Queue because they don't have a destination yet.

The metalink format is not very well designed for the FTP protocol. For example it doesn't support FTP over SSL etc.

Regards,
SmartFTP

eyebex
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Joined: Tue Jun 04, 2002 6:39 pm

Re: Metalink support

Post by eyebex » Fri Jan 19, 2007 11:54 pm

As I understand it, it does not make much sense to support Metalink in SmartFTP, because SmartFTP cannot (yet) download a single file from multiple servers, and that's the main purpose of Metalink: To list mirrors of a single file.

So it's important to understand SmartFTP will not parse all URLs listed in a <resources> section, but only add one of them (the first FTP URL). It only adds another URL if it occurs in a different <files> section. Put simply: Currently only adding one URL per <resources> section is supported.
Last edited by eyebex on Fri Jan 19, 2007 11:58 pm, edited 1 time in total.

twanj
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Re: Metalink support

Post by twanj » Sat Jan 20, 2007 1:59 am


mb
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Re: Metalink support

Post by mb » Sun Jan 21, 2007 12:26 am

Hello ...

>What do you need besides <url type="ftps">? Since metalinks are for listing the types that client programs support, it will be easy enough to add.
I think this should be sufficient. Right now SmartFTP will try to parse the URL if the type is set to "ftp" or "ftps". If the URL starts with "ftps://" SmartFTP assumes it's FTP over SSL.

>Just curious, I'm not familiar w/ XMD5 or XSHA which I see SmartFTP supports. I guess these are FTP server commands similar to Content-MD5 headers from web servers?
Yes that's correct. The client sends XMD5 <file> and the server returns the MD5 hash value. Unfortunately FTP servers under *nix do not support such features. However most FTP servers on MS Windows do.

>Will SmartFTP be able to use the MD5 or SHA1 checksums listed in metalinks to verify the downloads (or does it already)?
Yep the latest version (2.0.1001.26) does now ;-) Please give it a try.
https://www.smartftp.com/download

Regards,
-Mat

twanj
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Joined: Sat Sep 30, 2006 10:28 pm

Re: Metalink support

Post by twanj » Sun Jan 21, 2007 7:28 pm


mb
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Re: Metalink support

Post by mb » Mon Jan 22, 2007 6:25 pm

Thank you for the additional information on the partial checksums. However I think we will delay the support for partial checksums until we have the multi-part dowload feature ready.
I would appreciate if you could let me know about any future additions to the Metalink format which may benefit an FTP client like ours.
Best Regards,
-Mat

twanj
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Joined: Sat Sep 30, 2006 10:28 pm

Re: Metalink support

Post by twanj » Tue Feb 06, 2007 6:06 pm

Thank you for the additional information on the partial checksums. However I think we will delay the support for partial checksums until we have the multi-part dowload feature ready.
I would appreciate if you could let me know about any future additions to the Metalink format which may benefit an FTP client like ours.

I will. If you see any other areas of Metalink that need improvement, feedback is good

That will be great if you add multi-part downloads! It can really speed up downloads quite a bit.

twanj
Posts: 9
Joined: Sat Sep 30, 2006 10:28 pm

Re: Metalink support

Post by twanj » Tue Feb 27, 2007 6:19 pm

Here are some recent posts on metalink. The first one is particularly good.

http://www.geospatialsemanticweb.com/20 ... -downloads

http://slashdot.org/article.pl?sid=07/02/25/144209

mb
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Re: Metalink support

Post by mb » Tue Feb 27, 2007 9:08 pm

Thank you for the updates :-)
-Mat

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